The present invention relates to an automatically locking connector system for joining a first connector body with a second connector body. More particularly, the present invention relates to an automatically locking connector system that automatically disengages at a predetermined force.
Automatically locking connector systems are used for a variety of applications, such as electrical, fluidic, mechanical, optical, hydraulic or pneumatic systems, to provide a connection between various components and devices. A typical connector may comprise a female connector assembly and a male connector assembly that are designed to be engaged and disengaged with one another. Prior patents describe a coupling mechanism, having one coupler half that is inserted into the other half and a sleeve on one half, which rotates against a torsional spring force as a result of the camming action of complementary triangularly-shaped tabs on the sleeve and the inserted coupler half. The restoring force of the spring causes the sleeve to rotate into a locking position after the complementary tabs have passed each other. The tabs prevent disengagement of the coupler halves until the sleeve is twisted to permit the tabs to clear each other during uncoupling. For example, U.S. Pat. Nos. 5,067,909, 5,167,522 and 5,662,488, all of which are incorporated herein by reference, describe automatically locking couplers, in which a locking sleeve is rotated against a spring force during initial insertion of one coupler half into the other, and permitted to rotate back into a locking position upon completion of insertion.
With telescopically mating electrical connectors, such as a plug and a socket, it is often desirable or necessary to lock the two connector bodies together after their conductive contacts have been physically and electrically joined. Single conductor connectors with some form of bayonet joint may be rotated to a locking position. Multiple male and female contacts, however, must be slidingly joined telescopically without rotation, and typically have used a pliable plastic connector body which is deformed as a catch on one connector body rides over a detent on the other connector body to a locking position beyond the detent. If such a deforming latching body is frequently engaged and disengaged, the plastic tends to fatigue from the deformation. As a result, the latching mechanism eventually fails. In addition, care must be taken during assembly of the connector to ensure that the connectors fully engage with each other.
Most locking connectors are designed to lock in the mated position and must be manually disengaged. In certain applications, it is desirable that the connectors automatically disconnect when a force exceeding a predetermined level is applied to the connector assembly or a cable extending from the connector assembly. For example, requirements exist in some industries that a mated pair of connectors disengage (or break away) before the cable is damaged, the connector pair is damaged, personnel trip over the cord, electrodes connected to the connector are stripped off a patient (in medical applications) and/or attached equipment, such as an electronic device, falls and becomes damaged, falls from a shelf and crashes to the floor or falls in such a way to cause personal injury.
The present invention provides a breakaway locking connector configured to disengage at a predetermined force. The present invention combines a self-latching arrangement with an automatic de-coupling arrangement in a connector system. The breakaway locking connector comprises first and second tubular connector bodies having telescopingly engaged body portions and axially mating contacts, an annular collar rotatively held on the first body encircling the telescoping body portions and a spring inside the collar. The ends of the spring are confined between the first body and the collar so as to yieldingly resist rotation of the collar relative to the first body. Axially aligned tabs are provided on the collar and the second body for latching the first body and the second body together through a predetermined range of forces. The tabs include opposed flaring cam surfaces, which cause the collar to rotate relative to the second body as the first and second body are telescoped to a mated contact position. The cam surfaces guide the collar tab around the body tab, and the coiled spring yields as the collar is rotated by the cam tabs during contact mating to allow the collar tab to slide past the body tab. The spring then rotates the collar tab to a latching position axially behind the body tab, thereby locking the connector bodies in mated contact position. When a predetermined breakaway force is applied to the mated bodies, the body tab and the collar tab are configured to automatically disengage without damaging the components of the connector.